CVE-2026-27459
No exploitation reported by the sources we read.
- Published2026-03-18
- Fixed in26.0.0
- WeaknessCWE-120
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 22.0.0 and prior to version 26.0.0, if a user provided callback to `set_cookie_generate_callback` returned a cookie value greater than 256 bytes, pyOpenSSL would overflow an OpenSSL provided buffer. Starting in version 26.0.0, cookie values that are too long are now rejected.
Timeline
dates in UTC- 2026-03-1800:16CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-23 21:37 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-27459?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-27459?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD · OSV| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 26.0 | ≥ 22.0.0, < 26.0.0 | 26.0.0 | NVD · OSV |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Distribution builds and vendor advisories
Packages from OSV.dev and products from the vendors' CSAF advisories.
version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.
Vendor advisories
Red Hat Security Advisory: Red Hat Ansible Automation Platform 2.7 Container Release Update
Red Hat Security Advisory: Red Hat Ansible Automation Platform 2.6 Container Release Update
Red Hat Security Advisory: Technical preview of the satellite/iop-vmaas-rhel9 container image
Red Hat Security Advisory: Red Hat Quay 3.15.5
Red Hat Security Advisory: Red Hat Quay 3.17.2
Red Hat Security Advisory: Red Hat Quay 3.14.8
8 more advisories
Fix
- Update Pyopenssl to 26.0.0
- Vendor fix Red Hat Product Security RHSA-2026:87124 · 2 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://docs.redhat.com/en/documentation/red_hat_ansible_automation_platform/2.7#Upgrade
- Vendor fix Red Hat Product Security RHSA-2026:87120 · 4 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://docs.redhat.com/en/documentation/red_hat_ansible_automation_platform/2.6#Upgrade
- Vendor fix Red Hat Product Security RHSA-2026:68780 · 1 productFor Red Hat Lightspeed in Satellite installation see the Red Hat Satellite documentation.
- Vendor fix Red Hat Product Security RHSA-2026:24853 · 3 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
- Vendor fix Red Hat Product Security RHSA-2026:21017 · 4 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11458
- Vendor fix Red Hat Product Security RHSA-2026:13553 · 8 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://docs.redhat.com/en/documentation/red_hat_ansible_automation_platform/2.5#Upgrading
Advisories and patches
- github.comRelease Notes
- github.comPatch
- github.comVendor Advisory
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CVSS 4.0 vector
- CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Published
- 2026-03-18
- Last Modified
- 2026-09-10
- NVD status
- Modified
Frequently asked questions
What is CVE-2026-27459?
Is CVE-2026-27459 actively exploited?
What is the CVSS score for CVE-2026-27459?
Running pyopenssl? Hear about its next vulnerability
Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».
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Go further
- Following what attackers exploit right now? The CISA KEV additions of the month, with their patch deadlines.
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Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.